Various types of positioning elements are used, frequently by being controlled by mechanical drive arrangements, such as cams or the like, and often with springs interposed therebetween. Pneumatic, hydraulic, or electromagnetic drives may also be used. The positioning forces usually build up to a maximum force. As a consequence, the positioning element is subjected to a gradually increasing force and acceleration of the positioning element itself will be a function of the--gradually increasing--applied force. Extremely short positioning times, for example in the microsecond range, thus cannot be obtained with such positioning elements.
Piezoelectric elements have extremely short reaction times; they can switch states from between 10 to 100 microseconds (see, for example German Patent Disclosure Document DE-OS 20 28 442 to which British Patent No. 1,320,570 corresponds). The positioning distance of such elements, however, is extremely small--restricted to small fractions of a millimeter, thus severly limiting the application of piezoelectric elements for positioning components or devices to which they may be coupled.